Positive (Rei)nforcement
by Tillyalf427
Summary: Rei has been going to Samezuka and meeting with Rin for a few weeks now in an attempt to learn to swim all the different strokes. This week, however, Rin has an idea to help Rei out...


**A/n: For an asexual who hates the idea of sex, I really do write a lot of smut but I mean...¯\\_(ツ)_/¯**

**But hey, this happened I guess?**

**The only motivation I've had al month has been spent on this**

**And I desperately wanted to finish this because I thought of a pun for the title and I'm very proud of it uwu**

**~Enjoy~**

It was the same routine, day in, day out for Rei. Wake up, get ready for school, go to school, swim practise and then heading to Samezuka academy to train with Rin. It had been the same for the past few weeks and he had found that he didn't mind it, quite enjoying his time spent with the redhead.

Today was no different. As they finished up swim practice, Rei managed to brush off his teammate's requests to hang out, quickly dressing and making his way out as fast as possible before heading straight to the train station which would take him to Samezuka academy.

The sun was beginning to dip behind the skyline when he arrived at the academy, spotting Rin waiting by the gate for him and waving with a small smile, speeding up to reach him.

"Hey," Rin spoke casually when he was in earshot, walking alongside the Iwatobi swimmer. "You alright?"

Rei nodded absentmindedly

"They're starting to get suspicious about where I'm going, it's awfully hard to hide things from Nagisa,"

With a grin, Rin responded, opening the door to the pool and letting Rei inside first

"He is very insistent on knowing what people are doing,"

They caught up as they got changed before heading out to the pool, entering the water and beginning their training session.

"Let's start with backstroke," Rin suggested, helping Rei get into the correct position before ensuring he was ready and letting go.

He watched as Rei began swimming however, the Iwatobi swimmer had begun swimming the wrong way, running into the lane divider. The redhead quickly moved over to the other male with a small smile.

"I think I might know how to help you," Rin suggested, making a beckoning motion with his hand as he swam to the edge of the pool again, Rei following closely behind.

"Wait here,"

With that, Rin pulled himself out of the pool, water running off him as he quickly made his way to the changing rooms.

Rei's mind wandered whilst he waited for Rin, wondering what the redhead's idea was. Luckily for him, he didn't have to wait long as he heard Rin's voice coming from the changing rooms.

"Close your eyes, it's a surprise,"

He obeyed, his curiosity spiking even more as he heard wet footsteps approaching before a small splash as Rin slid back into the pool. He could tell where Rin was stood and was tempted to open his eyes before he felt the redhead's body pressing against him, pushing him against the wall.

"Rin-san? W..what are you doing?"

"Open your eyes,"

He obeyed, his eyes fluttering open as he tried to turn around to face the older male, only managing to catch sight of the side of his face.

"As I said, I think I have a way to help you," Rin began before presenting what was in his hand to Rei.

The younger male blushed bright red as his brain caught up and supplied him the knowledge of what Rin was currently holding.

Rin was currently holding out a silicone looking butt plug and Rei spluttered trying to think of what to say to the redhead.

"I figured, that maybe some positive reinforcement might help," He could practically feel Rin's grin as he spoke, "Obviously only if you're okay with it?" There was now a tinge of concern in Rin's voice and he backed away slightly.

Rei's hand quickly shot out behind him to grab Rin's wrist, looking at the redhead over his shoulder.

"Y...Yeah...I mean it's alright..."

Rin's surprise was obvious on his face as he asked

"Really?"

Rei gave a nod with a somewhat unsure smile over his shoulder and Rin gave a questioning look back.

"Sorry...I just didn't expect you to agree so quickly...I thought...Nevermind..."

"Just one thing...How would that work..?" Rei asked somewhat unsurely, Rin's grin returning immediately as he presented what was in his other hand.

A small remote control lay in his palm and as he flicked a switch on it, the butt plug sprang to life and began vibrating in his hand. Rei simply stared wide-eyed, a small "Oh," escaping his mouth as Rin grinned.

"When you get it right, I can use this to reward you," The redhead explained before gently pushing Rei against the wall again, reaching past him to place the objects in his hands on the poolside.

Rei gasped quietly as he felt Rin pressing up against him, the mood in the pool completely different to a couple of minutes ago. He noticed that there was also a bottle of lube placed nearby on the side of the pool which he had failed to spot before however, as he saw Rin reaching for it, he felt a spike of uncertainty.

"I've never done this before..." He voiced out and Rin froze for a moment before gently squeezing Rei's hip in reassurance.

"I'll be gentle I promise. If you change your mind or want to stop, tell me and I will. I don't want to force you to do anything,"

Rei nodded and took a deep breath.

"Yeah...I will..."

With that, the redhead spun Rei around, lifting him up so he sat on the edge of the pool before manoeuvring him to pull his swimsuit off him. It took a bit of fumbling however, he eventually managed it, lifting Rei's legs to rest on his shoulder as he pressed a hand to his chest to get him to lie down.

Next, Rin grabbed the lube once more, flicking the bottle open and coating his fingers in it before placing it back down within arms reach. Reaching down, he circled around Rei's entrance, pausing as the younger male tensed up and taking his hand, squeezing it reassuringly as he began inserting his index finger slowly, pausing when it was halfway in to look at Rei's facial expression.

"You alright?" Rin asked, his voice tinted with concern

Rei nodded quickly, pushing back against Rin's finger slightly.

"It's a little weird but not terrible...it doesn't hurt,"

With a nod, Rin continued, pushing his finger in the rest of the way before leaning down to kiss at Rei's inner thigh, sucking a large dark purple mark on the soft skin.

Rei left out a quiet noise as Rin began wriggling his finger slightly before pulling it out again, only to thrust it back in. This earned a choked noise from Rei and so he continued doing it until Rei let out a long whine, pleading whine.

"Please...Rin...I can take more...Please..."

"Shhh, Just leave it to me, okay?"

With that, Rin began gently easing another finger into Rei's entrance, pausing and speaking softly when Rei tensed up.

"You need to relax, I don't want to hurt you,"

The redhead began scissoring his fingers apart after thrusting them in a couple of times, carefully watching Rei's face for any signs of pain as he stretched him out slowly, each time bringing him just to the point of discomfort but never allowing it to become painful.

After slipping in a fourth finger, he tried spreading his fingers one last time before leaning over to look directly at rei.

"Do you think you're ready?"

The younger male nodded with a breathless gasp which turned into a whine as Rin began pulling his fingers out slowly, reaching to grab the butt plug from where he set it on the side of the pool. He also grabbed the bottle of lube and thoroughly coated the plug with the liquid before holding it up to Rei's entrance, gently applying pressure until it slipped past the ring of muscle. Moving slowly, he began inserting the plug, keeping a close eye on Rei's facial expression as he went and pausing occasionally to allow the younger male to adjust. A sharp gasp came from Rei as he reached the widest part of the plug, struggling to keep his muscles relaxed as Rin continued applying pressure to the end of the plug. In no time at all, the plug slipped in and Rei gasped loudly upon feeling the weight of it inside him, feeling his hips twitching against his will.

"It's alright, it's in," Rin spoke softly, running a reassuring hand down Rei's thigh "How does it feel?"

Taking a moment to catch his breath, Rei replied

"It's...intense...And big...I don't quite know if I'll be able to swim like this..."

"We can try if you'd like, or I could turn it on?"

"Ah...I forgot about that...damn..." Rei gasped before seeing Rin grinning, reaching for the small controller.

The redhead began turning a dial on the remote slowly and Rei felt his world screech to a stop as all of his focus centred around the sensation of the plug vibrating inside him.

"Ah...Rin...Fuck..."

"I never thought I'd see the day where Rei Ryugazaki would swear," Rin commented with a grin.

"...It's...ah...It's your fault...Ah..."

With a somewhat evil looking smirk, Rin quickly twisted the dial to turn the device off again, laughing slightly at the whines he received from Rei.

"Ah, ah, ah, I thought the purpose of this was to reward your swimming?" Rin teased, not missing the dramatic way in which Rei threw his head back.

"...Rin...Please..."

The redhead gave a stern look and Rei obeyed slowly moving back into the water, his movements stiff and uncoordinated as he tried not to move the plug around too much.

"Let's carry on with backstroke, okay?" Rin asked, not really expecting an answer.

Again he helped Rei get the correct position, hiding his grin as his hand moved further down than necessary, pressing against the plug and making Rei jolt in his hold with a loud gasp.

"Sorry, sorry, I couldn't help it," Rin smirked and Rei simply huffed slightly as this time Rin actually helped him get into the right position. As Rin let go of him, he began swimming, his movements uncomfortable as the pug shifted inside him with every movement. However, this time, he managed to avoid the lane dividers, gatting to the other end of the pool with Rin soon catching up to him, a wide grin of his face.

As Rei tried to catch his breath, holding onto the wall, Rin flicked the dial on the remote control, watching as Rei shuddered at the sudden sensation.

"You did well, Rei," The redhead whispered in his ear when he got close enough then lowered his voice even more "If you can do that with the other two strokes, I might just let you cum,"

Rei outright groaned at that before Rin turned the plug off again, feeling Rei thrusting back against him.

"No...please..."

"Do you want to try breaststroke now?" Rin completely ignored the protests from Rei and the Iwatobi swimmer had no choice but to agree, Rin once again helping him get the correct position before letting go and watching the other swim.

Rin repeated his previous actions when Rei reached the other side of the pool, watching the other shudder as the vibrations wracked through his body before turning it off again giving a cruel smile and more instructions.

"Freestyle now,"

An evil idea sprung into Rin's head and as he watched Rei swim, he began slowly increasing the intensity of the vibrations, clearly seeing the difference in the younger males swimming as he played with the remote, increasing and decreasing the intensity and watching with hawk-like eyes. Much to his surprise, Rei continued swimming and so, he decided to be cruel, turning the vibrations up all the way just as Rei was nearing the end of the pool. The younger male faltered and stopped swimming, his breathing coming out heavy as Rin swam quickly to catch up to him, wrapping muscled arms around him.

"Sorry, that was mean. You did well, so well...You've come far," Rin's voice was filled with pride as he pressed Rei against the wall again, his lips descending on the younger males neck, kissing and sucking all while he played with the dial on the remote. Rei's hips stuttered as he tried to grind against Rin's leg, the older male letting him as he marked his neck and chest.

"Ah...ah...Rin...Fuck...Rin.." Rei moaned shamelessly as he grinded against the redhead's thigh, the vibrations in his ass driving him crazy as the water splashed against their bodies and the wall.

"Do you think you can get off like this?" Rin asked, his breath hot against Rei's neck. The younger male nodded frantically and moved faster against Rin's leg as the redhead increased the intensity of the plug. "Come for me Rei," Rins voice was low, almost impossible to hear and it sent jolts down Rei's spine as the vibrations began to get too much. His hips bucked violently against Rin's thigh as he came, the plug still vibrating throughout his orgasm and overstimulating him as Rin bit down hard on his neck.

"Fuck..Fuck...Rin, Rin, Fuck, Ah...too much," Rei whimpered out, sensitive and worn out as Rin turned the plug off, stroking through Rei's hair.

"You did so well," Rei soaked up the reassurance and Rin continued "I really think you're ready to show them, even with me trying to throw you off you did it. You need to be more confident in yourself,"

As Rei slowly gained awareness of his surrounding, he remembered where they were and his face flushed bright red. He could feel Rin's hard dick pressing against his leg and he looked down awkwardly, speaking quietly

"Ah...Do you want me to...help?"

He reached down to cup Rin's dick however, the redhead brushed him off, wrapping his arms around Rei's still trembling form.

"No. You look exhausted, you need to rest," Rei looked almost disappointed and Rin added with a small smirk "Besides, there's always next time, I'm sure we'll meet again,"

Finally registering the sticky mess inside his swimsuit, Rei shifted in discomfort and Rin pulled away slightly.

"Come on, let's go and get changed, You still have the plug in as well, I'll take it out for you,"

Rei, being too tired to argue, agreed and allowed Rin to help him out of the pool and take his hand as they walked to the changing rooms.

The younger male allowed a lazy smile to grace his lips and leaned on Rin's shoulder slightly, suddenly feeling awfully tired. Rin noticed this as they showered together and so, after helping Rei get dressed and dressing himself, he took the Iwatobi swimmer's hand a tugged him the opposite way to that which he usually went, briefly explaining.

"You look really tired, I don't want you getting the train in case something happens,"

Rei simply agreed, practically falling asleep as he followed Rin. He couldn't be sure what happened after that, he was sure he heard Sousuke's voice at some point which would make sense seeing as he was Rin's roommate but he couldn't be sure what was said. The next thing he knew, he was wrapped up in Rin's arms in what he presumed was Rin's bed. Deciding not to question it, he relaxed, allowing his eyes to slip closed, missing Rin's fond smile as he watched him.

**A/n: Is it obvious that I never know how to end these things?**


End file.
